No Start, 1993 100CSQ Avant Auto

[LL - NY]

Although this is worth considering, I'm still suspecting fuel issues. Need to 
figure out fuel pump output tests without VAG-COM (mine's not here). 
Either that or jumpering the pump to see if it works. One thing at a time,
first fuel, then air, finally spark (how do you safely test spark with a POS
coil-less car anyway?). 

LL - NY

On Apr 9, 2005 12:29 PM, SJ <syljay at optonline.net> wrote:
> Sounds like a vacuum leak. You have a lean mixture that wont ignite.
> The engine runs for 15 seconds because the "cold start" injector is putting
> in extra fuel to richen the mixture.
> The computer shuts off the cold start injector after about 10 or 15 seconds
> . . .and the engine dies . . too lean.
> 
> Pull the electrical plug off the cold start injector and see if the engine
> will start. If it wont start, you have found your problem . . .air leak.
> 
> When does the engine restart? When you leave it alone for about 30 minutes?
> I think the computer puts a timer on the cold start valve, to keep the
> engine from flooding on restarts.
> 
> I think the cold start valve works on a 12 volt signal. You  can jump the
> valve with 12 volts to keep the engine running.
> If engine keeps running with cold start valve jumpered . . .its a vacuum
> leak problem.
> 
> SJ
> 85 Dodge PU, D-250, 318, auto
> 85 Audi 4k - - sold but still on the road
> 88 Audi 5kq
> 90 Audi 100q
> 
> > From: LL - NY <larrycleung at gmail.com>
> > Subject: No Start, 1993 100CSQ Avant Auto
> >
> > Trying to diagnose the above vehicle without the aid of a
> > Bentley's or VAG-COM (both rather packed away in storage,
> > helping out a friend).
> >
> > Symptoms: Car starts briefly, runs for about 15 seconds, then
> > slowly stalls. Will not restart. My hearing sucks, so I can't
> > tell if fuel pump is running, but it acts like there is no fuel. Car
> > cranks fine. Fuel pump fuse is fine (even swapped one to be sure)
> > Car does have about 198 k miles on it and has been reasonably
> > maintained.
> >
> > Several questions:
> >
> > Does the car use a Fuel Pump Relay? I searched the underhood
> > relay box and the drivers footwell area and found none.
> >
> > If it does use a relay, what pins would need to be shorted in order
> > to get the pump to run full time?
> >
> > Other than that, any other suggestions?
> >
> > TIA,
> >
> > LL - NY
> >
> >
> > ------------------------------